Various inventions have been created to file or abrade the surfaces and/or edges of objects, particularly when said object surfaces and/or ends are rough or dangerously sharp. Metal files, for example, come in a variety of shapes, materials, and teeth, but most are limited to a similar basic design: an elongated flattened blade having one or more filing surfaces, with forward-facing cutting small teeth on said surface(s). When pressure is applied from the teeth of the metal file to a rough or sharp surface of a work piece and the metal file is pushed over the work piece, the cutting action of the sharp teeth can smooth the surface. Different configurations of teeth facilitate different cutting motions of the metal file. By scratching or rubbing rather than cutting, various abrading devices also have been used to smooth the metal surface of a work piece. In addition, some clamping or similar mechanisms allow easier filing or abrading/sanding by holding the position of a work piece in place. Some motorized devices allow surfaces to be abraded or filed more quickly.
Such traditional metal files, abrading devices, clamping devices, and motorized devices, may be effective at performing their anticipated functions but are not optimally designed for certain applications. Specifically, such prior designs may not be optimal for filing the edges of objects or work pieces having particular geometric shapes in an efficient, safe, and relatively quick and simple manner. Namely, certain work pieces comprising several edges on different non-linearly arranged planes may make filing with prior art files and abrading devices awkward, less efficient, more time-consuming, and more dangerous. Moreover, using prior art devices to file certain edges of such somewhat complex shapes may present difficulty or even risk of injury.
For example, one common object or work piece comprising multiple nonlinear adjacent surfaces having potentially dangerous rough or sharp edges is metal strut. Metal strut is used in a wide variety of commercial and industrial support systems and is usually in the shape of a hollow box channel (usually either 1⅝ inch by 1⅝ inch or 1 inch by 1 inch). Moreover, metal strut is often cut in smaller pieces for customization according to objective and application. The cut edges of the metal strut are often sharp and may pose risk of injury. Several devices have been created with the objective of avoiding this risk of such injury. For example, strut end caps have been created for placement over and covering the ends of a strut. However, when a strut channel is not cut perfectly straight with respect to the latitudinal axis, said end caps may not fit quite correctly. Moreover, heat generated from cutting a metal strut may sometime cause the shape of the metal strut to warp, also resulting in an end cap not fitting correctly. Certain prior art strut channel designs may try and avoid injury from sharp edges, by for example incorporating strut ends that may bend or are less likely to have sharp edges, but may not be as effective at reducing sharp or rough edges when the strut channel is cut, and may not solve the problem of sharp or rough edges when using standard or more common designs of metal strut.
Thus, the edges of cut metal strut are often filed and/or abraded using standard metal files or abrading devices. When trying to file the inside edges of the box with a traditionally-shaped file, however, the motion of the elongated blade may be restricted by the wall of the strut wall opposite from the edge being filed. Similarly, mechanical abrading devices may have designs that make abrading the inside edges of a strut channel awkward and less than optimally effective. In addition, since there often may be no clamp handy to hold the strut in a stable position, cut metal strut being filed may often be held in place by hand, which may increase the risk that an errant strike will cause injury to the hand. Risk of injury is compounded by the fact that cut strut channels may often have sharp and rough areas along both the inside and outside edges of multiple surfaces of a strut.
Moreover, most prior art filing and abrading device designs normally allow only one surface of a device to be placed against one work piece surface (or one edge of a surface) at a time. Thus for work pieces requiring the filing or abrading of multiple nonlinear surfaces (or edges thereof), when one work piece surface has been filed or abraded sufficiently, the position of the filing/abrading device and/or the work piece must normally be substantially adjusted in order for the next work piece (or object) surface or edge of a work piece surface to be filed. This repositioning may result in more time being required for filing a work piece. For example, in some cases it may take around two to three minutes to file all the edges of one strut end. The inefficiency of excessive repositioning may be compounded by many separate work pieces having surfaces needing to be smoothed. For example, it is not unusual for some projects utilizing cut strut channels to entail many cut strut ends with surfaces and/or edges that require filing.